diff --git a/src/UiEffects.js b/src/UiEffects.js
new file mode 100644
index 0000000000..76db0b7f12
--- /dev/null
+++ b/src/UiEffects.js
@@ -0,0 +1,27 @@
+/*
+Copyright 2016 OpenMarket Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * Functions for applying common thematic effects to  UI elements.
+ * Ideally this would be themeable.
+ */
+
+import Velocity from 'velocity-vector';
+import 'velocity-vector/velocity.ui';
+
+export function field_input_incorrect(element) {
+    Velocity(element, "callout.shake", 300);
+}
diff --git a/src/components/structures/login/Login.js b/src/components/structures/login/Login.js
index a73ad30f87..74edc4ecd9 100644
--- a/src/components/structures/login/Login.js
+++ b/src/components/structures/login/Login.js
@@ -53,6 +53,7 @@ module.exports = React.createClass({displayName: 'Login',
         return {
             busy: false,
             errorText: null,
+            loginIncorrect: false,
             enteredHomeserverUrl: this.props.customHsUrl || this.props.defaultHsUrl,
             enteredIdentityServerUrl: this.props.customIsUrl || this.props.defaultIsUrl,
 
@@ -68,13 +69,15 @@ module.exports = React.createClass({displayName: 'Login',
     onPasswordLogin: function(username, password) {
         var self = this;
         self.setState({
-            busy: true
+            busy: true,
+            errorText: null,
+            loginIncorrect: false,
         });
 
         this._loginLogic.loginViaPassword(username, password).then(function(data) {
             self.props.onLoggedIn(data);
         }, function(error) {
-            self._setErrorTextFromError(error);
+            self._setStateFromError(error, true);
         }).finally(function() {
             self.setState({
                 busy: false
@@ -100,7 +103,7 @@ module.exports = React.createClass({displayName: 'Login',
         this.setState({
             enteredIdentityServerUrl: newIsUrl
         }, function() {
-            self._initLoginLogic(null, newIsUrl);            
+            self._initLoginLogic(null, newIsUrl);
         });
     },
 
@@ -120,7 +123,7 @@ module.exports = React.createClass({displayName: 'Login',
             // logins so let's skip that for now).
             loginLogic.chooseFlow(0);
         }, function(err) {
-            self._setErrorTextFromError(err);
+            self._setStateFromError(err, false);
         }).finally(function() {
             self.setState({
                 busy: false
@@ -131,7 +134,8 @@ module.exports = React.createClass({displayName: 'Login',
             enteredHomeserverUrl: hsUrl,
             enteredIdentityServerUrl: isUrl,
             busy: true,
-            errorText: null // reset err messages
+            errorText: null, // reset err messages
+            loginIncorrect: false,
         });
     },
 
@@ -139,25 +143,30 @@ module.exports = React.createClass({displayName: 'Login',
         return this._loginLogic ? this._loginLogic.getCurrentFlowStep() : null
     },
 
-    _setErrorTextFromError: function(err) {
+    _setStateFromError: function(err, isLoginAttempt) {
+        this.setState({
+            errorText: this._errorTextFromError(err),
+            // https://matrix.org/jira/browse/SYN-744
+            loginIncorrect: isLoginAttempt && (err.httpStatus == 401 || err.httpStatus == 403)
+        });
+    },
+
+    _errorTextFromError(err) {
         if (err.friendlyText) {
-            this.setState({
-                errorText: err.friendlyText
-            });
-            return;
+            return err.friendlyText;
         }
 
-        var errCode = err.errcode;
+        let errCode = err.errcode;
         if (!errCode && err.httpStatus) {
             errCode = "HTTP " + err.httpStatus;
         }
 
-        var errorText = "Error: Problem communicating with the given homeserver " +
+        let errorText = "Error: Problem communicating with the given homeserver " +
                 (errCode ? "(" + errCode + ")" : "")
 
         if (err.cors === 'rejected') {
             if (window.location.protocol === 'https:' &&
-                (this.state.enteredHomeserverUrl.startsWith("http:") || 
+                (this.state.enteredHomeserverUrl.startsWith("http:") ||
                  !this.state.enteredHomeserverUrl.startsWith("http")))
             {
                 errorText = <span>
@@ -173,9 +182,7 @@ module.exports = React.createClass({displayName: 'Login',
             }
         }
 
-        this.setState({
-            errorText: errorText
-        });
+        return errorText;
     },
 
     componentForStep: function(step) {
@@ -186,7 +193,9 @@ module.exports = React.createClass({displayName: 'Login',
                         onSubmit={this.onPasswordLogin}
                         initialUsername={this.state.username}
                         onUsernameChanged={this.onUsernameChanged}
-                        onForgotPasswordClick={this.props.onForgotPasswordClick} />
+                        onForgotPasswordClick={this.props.onForgotPasswordClick}
+                        loginIncorrect={this.state.loginIncorrect}
+                    />
                 );
             case 'm.login.cas':
                 return (
@@ -221,7 +230,7 @@ module.exports = React.createClass({displayName: 'Login',
 
         var returnToAppJsx;
         if (this.props.onCancelClick) {
-            returnToAppJsx = 
+            returnToAppJsx =
                 <a className="mx_Login_create" onClick={this.props.onCancelClick} href="#">
                     Return to app
                 </a>
diff --git a/src/components/views/login/PasswordLogin.js b/src/components/views/login/PasswordLogin.js
index c5474f60c1..1a40ddde6b 100644
--- a/src/components/views/login/PasswordLogin.js
+++ b/src/components/views/login/PasswordLogin.js
@@ -14,8 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-var React = require('react');
-var ReactDOM = require('react-dom');
+import React from 'react';
+import ReactDOM from 'react-dom';
+import classNames from 'classnames';
+import {field_input_incorrect} from '../../../UiEffects';
+
 
 /**
  * A pure UI component which displays a username/password form.
@@ -28,6 +31,7 @@ module.exports = React.createClass({displayName: 'PasswordLogin',
         initialPassword: React.PropTypes.string,
         onUsernameChanged: React.PropTypes.func,
         onPasswordChanged: React.PropTypes.func,
+        loginIncorrect: React.PropTypes.bool,
     },
 
     getDefaultProps: function() {
@@ -36,6 +40,7 @@ module.exports = React.createClass({displayName: 'PasswordLogin',
             onPasswordChanged: function() {},
             initialUsername: "",
             initialPassword: "",
+            loginIncorrect: false,
         };
     },
 
@@ -46,6 +51,16 @@ module.exports = React.createClass({displayName: 'PasswordLogin',
         };
     },
 
+    componentWillMount: function() {
+        this._passwordField = null;
+    },
+
+    componentWillReceiveProps: function(nextProps) {
+        if (!this.props.loginIncorrect && nextProps.loginIncorrect) {
+            field_input_incorrect(this._passwordField);
+        }
+    },
+
     onSubmitForm: function(ev) {
         ev.preventDefault();
         this.props.onSubmit(this.state.username, this.state.password);
@@ -72,14 +87,19 @@ module.exports = React.createClass({displayName: 'PasswordLogin',
             );
         }
 
+        const pwFieldClass = classNames({
+            mx_Login_field: true,
+            error: this.props.loginIncorrect,
+        });
+
         return (
             <div>
                 <form onSubmit={this.onSubmitForm}>
-                <input className="mx_Login_field" ref="user" type="text"
+                <input className="mx_Login_field" type="text"
                     value={this.state.username} onChange={this.onUsernameChanged}
                     placeholder="Email or user name" autoFocus />
                 <br />
-                <input className="mx_Login_field" ref="pass" type="password"
+                <input className={pwFieldClass} ref={(e) => {this._passwordField = e;}} type="password"
                     value={this.state.password} onChange={this.onPasswordChanged}
                     placeholder="Password" />
                 <br />
@@ -89,4 +109,4 @@ module.exports = React.createClass({displayName: 'PasswordLogin',
             </div>
         );
     }
-});
\ No newline at end of file
+});
diff --git a/src/components/views/login/RegistrationForm.js b/src/components/views/login/RegistrationForm.js
index 39c1acc625..33809fbfd6 100644
--- a/src/components/views/login/RegistrationForm.js
+++ b/src/components/views/login/RegistrationForm.js
@@ -17,8 +17,7 @@ limitations under the License.
 'use strict';
 
 var React = require('react');
-var Velocity = require('velocity-vector');
-require('velocity-vector/velocity.ui');
+var UiEffects = require('../../../UiEffects');
 var sdk = require('../../../index');
 var Email = require('../../../email');
 var Modal = require("../../../Modal");
@@ -117,7 +116,7 @@ module.exports = React.createClass({
             promise.finally(function() {
                 ev.target.disabled = false;
             });
-        }        
+        }
     },
 
     /**
@@ -196,7 +195,7 @@ module.exports = React.createClass({
         fieldValid[field_id] = val;
         this.setState({fieldValid: fieldValid});
         if (!val) {
-            Velocity(this.fieldElementById(field_id), "callout.shake", 300);
+            UiEffects.field_input_incorrect(this.fieldElementById(field_id));
             this.props.onError(error_code);
         }
     },
@@ -214,12 +213,13 @@ module.exports = React.createClass({
         }
     },
 
-    _styleField: function(field_id, baseStyle) {
-        var style = baseStyle || {};
+    _classForField: function(field_id, baseClass) {
+        let cls = baseClass || '';
         if (this.state.fieldValid[field_id] === false) {
-            style['borderColor'] = 'red';
+            if (cls) cls += ' ';
+            cls += 'error';
         }
-        return style;
+        return cls;
     },
 
     render: function() {
@@ -227,10 +227,10 @@ module.exports = React.createClass({
         var emailSection, registerButton;
         if (this.props.showEmail) {
             emailSection = (
-                <input className="mx_Login_field" type="text" ref="email"
+                <input type="text" ref="email"
                     autoFocus={true} placeholder="Email address (optional)"
                     defaultValue={this.props.defaultEmail}
-                    style={this._styleField(FIELD_EMAIL)}
+                    className={this._classForField(FIELD_EMAIL, 'mx_Login_field')}
                     onBlur={function() {self.validateField(FIELD_EMAIL)}} />
             );
         }
@@ -250,22 +250,22 @@ module.exports = React.createClass({
                 <form onSubmit={this.onSubmit}>
                     {emailSection}
                     <br />
-                    <input className="mx_Login_field" type="text" ref="username"
+                    <input type="text" ref="username"
                         placeholder={ placeholderUserName } defaultValue={this.props.defaultUsername}
-                        style={this._styleField(FIELD_USERNAME)}
+                        className={this._classForField(FIELD_USERNAME, 'mx_Login_field')}
                         onBlur={function() {self.validateField(FIELD_USERNAME)}} />
                     <br />
                     { this.props.guestUsername ?
                         <div className="mx_Login_fieldLabel">Setting a user name will create a fresh account</div> : null
                     }
-                    <input className="mx_Login_field" type="password" ref="password"
-                        style={this._styleField(FIELD_PASSWORD)}
+                    <input type="password" ref="password"
+                        className={this._classForField(FIELD_PASSWORD, 'mx_Login_field')}
                         onBlur={function() {self.validateField(FIELD_PASSWORD)}}
                         placeholder="Password" defaultValue={this.props.defaultPassword} />
                     <br />
-                    <input className="mx_Login_field" type="password" ref="passwordConfirm"
+                    <input type="password" ref="passwordConfirm"
                         placeholder="Confirm password"
-                        style={this._styleField(FIELD_PASSWORD_CONFIRM)}
+                        className={this._classForField(FIELD_PASSWORD_CONFIRM, 'mx_Login_field')}
                         onBlur={function() {self.validateField(FIELD_PASSWORD_CONFIRM)}}
                         defaultValue={this.props.defaultPassword} />
                     <br />